What can colleges see?

Sorry if this question has been asked a million times, but in terms of SAT subject tests, what can colleges see? For example, if I do very well on lit and us history, but do terribly on math 2, can I choose to only send lit and US history, or will they see all three scores?

My understanding is that they don’t see any scores unless you send them.

Agreed; they will only see what you send them. However, some colleges require that all scores be sent, so check out specific requirements. Additionally, some HS’s put standardized test scores on the transcript, so you should check with your GC.